
A few hundred gold query rewrites, \((\lbrace Q,\mathcal {H}\rbrace , \hat{Q})\) , where \(\hat{Q}\)  is the standalone query, manually rewritten based on search query \(Q\)  and its conversational context \(\mathcal {H}\) , as in the CANARD dataset [1]};

A few labeled query-context-document pairs, \((\lbrace Q,\mathcal {H}\rbrace ,D^+)\)  (or \((\lbrace Q,\mathcal {H}\rbrace ,D^-)\) ), where \(D^+\)  (or \(D^-\) ) is labeled as relevant (irrelevant) to \(Q\)  and its conversational context \(\mathcal {H}\) ; and

A well-trained ad hoc dense retrieval model, e.g., ANCE [2]}, which uses the dual-encoder architecture.

